this.addEventListener("install", function (event) {
  event.waitUntil(
    caches.open("v1").then((cache) => {
      return cache.addAll(["/service_work/aa.js"]);
    })
  );
});

this.addEventListener("fetch", (event) => {
  event.respondWith(
    caches.match(event.request).then((response) => {
      //   return response || fetch(event.request);
      return new Response(
        "<pa>Hello from your friendly neighbashood service workera!</pa>",
        {
          headers: { "Content-Type": "text/html" },
        }
      );
    })
  );
});
